Custom item GUI crashes the game.. again

I made a few things with GUI, the block works, but the items dont, the item gui with slots doesnt work even though i have 1 slot and i put 1+1 slots in it, and it used to work, now it doesnt, same when i make more slots and increase the number, still doesnt work, crashes the game, and now i made an item with no slots at all, and even that still crashes, wtf? why is this happening? might be the new update to 2021.2? because i didnt think the patch notes included "item GUIs now crash the game", i have spent 3 days trying to figure out why and i go no clue, please help me out devs, and please dont just say "go to this person to get started on MCreator" that doesnt help very much